The comparison between London and New York might be less about London becoming more of a hellhole and more about New York City becoming amazingly less of one. In 1990 that American city had 2,245 murders, and as the Financial Timesreports, “In the 20 years to 2009, the number of murders, robberies and burglaries in New York was down 80 per cent, twice the US national average, and lower than it had been in 1961.” While London has more and more relied on racially unbalanced stop-and-frisk searches to futilely cope with crime, New York has found that curtailing those practices, has not, despite law-and-order fears, led to increasing crime.

says that it was unlikely that “lack of deterrence” was the catalyst for the rise in serious violence. “Forces with the biggest falls in police numbers are not seeing the biggest rises in serious violence.”

Writing before the launch of her strategy to counter violence, [Home Secretary Amber] Rudd said in a Sunday Telegraph article: “While I understand that police are facing emerging threats and new pressures—leading us to increase total investment in policing—the evidence does not bear out claims that resources are to blame for rising violence.

“In the early [90s], when serious violent crimes were at their highest, police numbers were rising. In 2008, when knife crime was far greater than the lows we saw in 2013-14, police numbers were close to the highest we’d seen in decades.”

While simplistic blame for London’s murder problem is also aimed at social media in general and the rise of “UK drill” hip-hop in particular, one important lesson here is old and applies across the globe: Whatever weapons are or are not available, or legal, or used to harm others (acid attacks are also on the rise in London), keeping a desired commodity like drugs illegal and crammed into a black market with no legal recourse for conflict resolution is a terrible idea for domestic tranquility; and no amount of legal anathemas on mere tools, whether knives or guns or acid, is sufficient (or necessary) to reduce crime.